Concrete form



Nov. 13, W34, J. T. BLAIR- in AL CONCRETE FORM Filed Jan. 17, 1930 3Sheets-Sheet l NmN IINVENTORS Nov. 13, 1934.

H J. T. BLAIR ET! AL CONCRETE FORM 3 Sheets-Sheet 2 Filed Jan. 1'7, 1930Nov. 13, 1934. J L R r AL CONCRETE FORM 3 Sheets-Sheet 3 Filed Jan. 17,1930 Patented Nov. 13, 1934 UNITED STATES lawn PATENT OFFICE ApplicationJanuary. 17,

1930, Serial No. 421,530

7 Claims. (01. 25-1315) of pan as well as stock material such as isordi-' narily furnished by any lumber yard. 1

Another object of the invention is to make the pans adjustable inrespect to each other in the direction of what is herein known as thelength of the series, so that a given set of pans can be made to producean even number of coffered panels without cutting the pans.

A further object of the invention is to readily produce an adjustment ofthe distance between joist centers by adjusting the pans in thedirection of what is herein known as the width of the series, thisadjustment being accomplished by merely changing the width of thepansupports.

A still further object of the invention is to make the installment ofsuch electrical accessories as outlet boxes an operation simultaneouswith the erection of the forming, a particularly important advantagebeing the immediate access which may be had to such fixtures when theconcrete has set and the forming has been removed.

Another object of the invention is to provide a forming that can be puttogether in such a way that all parts of it with the exception of thejoist bottoms and shoring may be removed, enabling access of the air topractically all of the concrete or other surface to facilitate drying.

()ther objects and advantages will appear in the followingspecification, reference being had to the accompanying drawings inwhich,

Figure 1 is a perspective view of the parts of the forming constitutingthe improved mold, portions being shown in section.

Figure 2 is a perspective view of the spreader and crotch illustratingits application to a purlin.

Figure 3 is a cross section illustrating the use of double wedges inconnection with the spreader for the purpose of a wide spacing of thejoists on centers.

Figure 4 is a detail cross section particularly illustrating how anelectrical fixture, for example an outlet box, may be embodiedsimultaneously with the erection of the forming.

Figure 5 is a cross section similar to Figure 3 illustrating the use ofsingle wedges for a narrower spacing of the joists on centers.

Figure 6 is a similar cross section illustrating the use of a shorterspreader and but a single wedge in producing a still narrower spacing ofjoists on centers.

Figure 7 is a longitudinal section taken in the direction of the lengthof the pan series, illustrating an expansion of the pans to fullcapacity.

Figure 8 is a similar view illustrating the full contraction of thepans.

Figure 9 is a cross section illustrating an arrangement for producing afiat slab or colferedpanel ceiling, this arrangement being especiallyadapted to suspended ceilings.

Figure 10 is a plan view of the pans when arranged for the production ofthe foregoing ceiling.

Figure 11 is an inverted plan view of the finished coffered-panelceiling.

Figure 12 is a cross section somewhat on the order of Figure 5illustrating an omission of the pans for the purpose of producing a fiator unpaneled ceiling between joists.

This invention is an improvement on the concrete molds of Oscar L. Gentdisclosed in Patents No. 1,494,538 of May 20, 1924 and No. 1,601,- 389of September 28, 1925. The purposes of these patented structures are toprovide adjustable concrete molds which among other things, are capableof producing various arrangements of joists. A feature of Patent No.1,601,389 is a certain dome plate which acts as a cover for arectangular space defined by certain parts of the mold,'and like thoseparts is removable when the forming is taken down.

The foregoing dome plate is herein identified as the pan 1 whichconstitutes a coffer-shaping means. A large number of the pans will bemade use of, a standard size being 20 x 2". Usually the pans will beconstructed of 2" x 8" lumber, secured together in any ordinary way aswell as suitably reinforced so that damage may not be sustained whendropping the pans through great distances as in disassembling theforming.

Each panl is bevelled on all four edges as at 2. The purpose of the pansis to produce a coffered or paneled ceiling, the bevelling at the edgesbeing a most important contribution to an attractive result. In practicethe finishing of the pans is not confined to bevelling because the edgescan be rounded or otherwiseformed in any desired manner.

Instead of making the pans of wood they may be produced in concrete andin such instance may also be ornamented for the decoration of thecoffers. Concrete pans should be well oiled or otherwise treated so thatthe plastic material will not no adhere to them. In no instance are thepans retained as a part of the ceiling, the removability of the pans aswell as other parts of the forming being a feature of the invention.

Secured to the nether part of each pan 1 is an extension bottom 3. Thisis usually made by securing two 1 x 8s to the bottom of the pan. Spaces4 are thus left at the sides of the pan (Figs. 3 to 6) but the extensionbottom is offset in its application (Figs. '7 and 8) so that a tongue 5wise of the sheet and the side edges alluded to arethose that runparallel to the length of the series. These terms are an arbitraryselection used for convenience in future reference.

Pan supports '7, 8 provide rests for the side edges of the pans. It isupon these pan supports that the longitudinal series ofpans l areassein-- bled. The extension bottoms 3fit between the parallel pansupports, the latter providing guides along which the pans may be slidin producing the desired adjustment of the pans in respect to each otherin the direction of the length of the series.

Various widths of pan supports 7, 8 can be used, this depending upon thedesired spacing of joists 9 (Figs. 3 to 6) on centers. The pan supportsmay comprise l x 4s, 1 x 5s, v1 x 8s, etc., the width of the pansupports being a direct gauge to the spacing of the joists oncenters.

For example, Figure 3 illustrates the use of pan supports 7, 8 of 1 x '1stock. In Figure 5 1 x 6s are substituted while in Figure 6 1 x 4s areused. This produces a contraction in the spacing between centers of thejoists 9, and as already indicated, this particular adjustment is solelya function in the regulation of the width of the pan supports 7, 8. i

' Light nails 10 are driven through the pan supports 7, 8 from aboveinto the confronting joist sides 11, 12 constituting the joist-shapingmeans,

to the. upper edgesof which the pan supports are applied substantiallyas shown. The joist sides in turn may be secured by nails 13 to theedges of the joist bottoms l4. Howeventhese the series of pans 1 as dothe pan supports 7. 8.

It ,is to be observed that the joist bottoms are fitted between thepairs of sides 11, 12 and that the latter, in most instances, come flushwith the lower surfaces of the joist bottoms.

This particular arrangement makes it easy to drive a sharp instrumentinto the joint between the side 11 preparatory to taking down most ofWhen the joist sides are loosened the pan supports '7, 8 as well as thepans will the forming;

readily fall apart either in whole or in part, leaving most of theformerly plastic surface exposed to the for ready drying.

A number of purlins 15 are extended crosswise of the forming. These aresuitably secured in the gains 16 (Figs. 1 and 2) of shores 17. Theshores should be so spaced that they will come below the joists 9 sothat when the purlins 15 are knocked away with the rest of the formingThe length of the series re-,

The front and rear edges simply placed on the pan 1 so that when the panthe shoring will still afford the major support for the cast work, andthe advantage of that support may be had until the work has driedthoroughly.

The upper ends of the shores will bear against the joist'bottoms 14,which are retained for the time being, but the joist bottoms 14 cover solittle of the cast surface that the process of drying is not affected toany noticeable extent. The supporting advantage'that the shoring andjoist bottoms 14 afford ofl'sets' the retardation in drying to such asmall extent that this is totally negligible.

Spreaders 13 have crotches 19 that fit over the purlins 15 so as to keepthe spreaders in place in the spaces between the joists 9. The,spreaders rest upon the purlins and support both the otherwise freeedges of the pan supports 7- and 8, hence the pans '1. Wedges 20 areused in conjunction withthe ends of the Spreaders, and the number ofwedges to be used depends upon the desired balancing of the joistsbetween centers.

For example, Figure 3 which shows a wide spacing of joists-9 on centersillustrates the use of pairs of wedges at the opposite ends of thespreader 18. Figure 5, in which there is a lesser spacing between thejoists,illustrates the use of single wedges at the opposite ends of thespreader, while Figure 6, in which the spacing between joist centers isstill less illustratesthe use of not only a single wedge but also ashorter spreader.

The purpose of the wedges is to hold the joist sides 11, 12 plumb and topress these so tightly against the edges of the joist bottoms 14 thatthere will be no leakage of concrete at the joint.- The joist bottomsand sides'are usually made by 110 2 x 8 stock thus insuring, especiallyin the instance of the joist sides, an adequate co-action with thewedges 20.

Adjustments as to the depth of the joists 9 are made by'placing a one totwo inch block 21 (Figs. 115 5 and 6) under the joist bottoms .14 wherethey cross the shoring 17. Figure 5 illustrates the use of a one inchblock while Figure 6 shows the use of a two inch block. The result is'alessening of the depth of the joist.

Electrical fixtures, such as an outlet box 22, (Fig. 4) are readilyincorporated in the plastic material and are put inplace simultaneouslywith the erection of the forming. The box is is removed immediate accesswill 'be had to the box inasmuch as the opening thereinto will be flushwith the surface of the coder. This facility is a decided advantage inplastic construction because it does notlater become necessary to cutout recesses and channels for the boxes and condult. 1

Figures 7 and 8 illustrate the adju'stability of the pans in thedirection of the length of the series. The extension bottoms3 fill inthe gap 23 between the pans and define the bottoms of cross ribs whichare broadest when the pans are fully expanded (Fig. 7) and narrowestwhen the pans are fully contracted (Fig. 8).

'When the pans are disposed as in Figure 7 they are 1 11 on centers. InFigure 8the same series of pans is fully contracted to a spacing of 1 9on centers. This adjustability of the pans makes it possible to spacethem to suit any room width and makes it possible to produce an evennumber of coffered panels without cutting 9, 10 and 11 illustrate thisphase of the invention. The pans 1 are rested at their-side edges upon 2x 8 plank 23. These are rested upon the purlins l5 and the shoring 1'7will be situated at selected distances asbefore.

The extension bottoms 3 drop down between the planks 24; which thus holdthe pans'in line (Fig. 10), the tongues 5 of the extension bottomsfilling the spaces between the pans when it is found necessary to expandthe pans in order to obtain an even spacing along the series.

In Figure 10 the pans 1 are fully contracted as, for example, in Figure8. Figure 11 illustrates the ceiling produced by the forming in Figures9 and 10; Should it be found that the 2 x 8 planks 24 (described inconnection with Figure 9) do not space out properly in the directionofone dimension of the room they may be substituted by 2 x 10s, 2 x 12s,or planks of such other dimensions that will produce the desiredspacing.

The type of construction illustrated in Figures 9, 10 and 11 isespecially adapted to suspended ceilings. Such ceilings would occur onthe nether side of balconies that are supported from the main ceiling orelsewhere by suspension rods. The joists are omitted, it being notedthat the planks 2 1 occur where the joist sides and bottoms appear inFigures 1, 3, etc.

Sometimes the requirement of the lowest possible cost, as in some kindsof commercial work, it becomes necessary to omit the pans 1 from theforming. All parts of the latter will be utilized as in Figure 12 as isindicated by the corresponding reference numerals, the space between thepan supports '7, 8 formerly occupied by the extension bottom 3, simplybeing filled with boards 25 of proper Widths, or some equivalent filler.The fi'ler 25 as well as the pan supports '7, 8 will rest on thespreader 18 as in former instances, the

result being a plain ceiling rather than a cofiered arface as when thepans are used.

The advantages and operation may be reviewed briefly. The outstandingimprovements over the two patents previously mentioned comprise thespreader 18, the pan supports '7, 8 and the adjustable feature of thepans 1. The longitudinal adjustment of the pans between the pan supports'7, 8 make it possible to evenly distribute the pans over any distancewithout cutting the pans.

While the pan supports '7, 8 are not inherently adjustable, that is tosay they cannot be stretched or contracted, yet they are adjustable inthe sense that they may be substituted for by wider or narrower pansupports when it is desired to alter the distance between centers of theconcrete joists 9.

In the erection of the forming the purlins 15 are secured in the gains16 of the shores 1'7. The joist bottoms 14 are laid crosswise of thepurlins Fig. 1) The joist sides 11, 12 are secured by nails 13 to theside edges of the joist bottoms. This makes the joist accessible so thata sharp instrument can later be driven in to separate the sides from thebottoms as in taking down the forming.

This can be done without damaging the edges of the concrete joist 9.

The spreaders 18 are merely seated on top of the purlins 15, thecrotches 19 affording the necezsary temporary support. After securingthe pan supports '7, 8 to the joist sides 11, 12, properly spacing thepans 1 longitudinally of the guides that the supports '7, 8 afford anddriving the wedges 20 so as to keep the sides 11, 12 plumb andleak-proof, the concrete may be poured. The necessary reinforcing rods(Figs. 1 and 3), and

any desired fixtures 22, (Fig. 4) would be fitted in place first.

At least the Spreaders 18 and wedges 20 willseparate from the forminguponknocking the purlins 15 from the shores 17. The remaining formingwill come loose from the concrete work merely by virtue of its weightupon prying the joist sides 11, 12 from the joist bottoms 14. The latterwill be left in place so that the shores 17 may support the work duringthe completion of the drying process.

The improved concrete mold is of the utmost flexibility. Adjustments ofthe spacing of the coffers produced by the pans 1 are possible both inthe direction of the length and width of the room. The adjustment of thecrosswise spacing of the coffers and the distance between centers of thejoists 9 are results which go together. The variations of the depth ofthe joists 9 are obtained by simply using blocks 21 of the properthickness. Thus there is no feature that is not capable of adjustment,the ultimate result being that an orderly distribution of joists andcoffers can be made in the ceiling of any room regardless of what thepeculiar dimensions may be.

While the construction and arrangement of the improved concrete mold isthat of a generally preferred form, obviously modifications and changesmay be made without departing from the spirit of the invention or thescope of the claims.

We claimz- 1. Apparatus for producing coifere'd and joisted ceilingscomprising a plurality of selectively spaced and similar means forshaping the joists, a pliu'ality of spaced and similar means for shapingthe coffers between each pair of adjacent joists, means extending alongand above and supported by the side walls of the joist-shaping meansproviding supports for the intervening cotter-shaping means and ofsufficient width to support the latter to agree with the chosen joistspacing, and means of sufilcient width for closing the spaces betweenthe coffershaping means in the direction of the joists to permitselective spacing of the desired number of cotter-shaping means.

2. Apparatus for producing coifered and joisted ceilings comprising aplurality of selectively spaced and similar means for shaping thejoists, a plurality of spaced and similar means for shaping the coffersbetween each pair of adjacent joists, means extending along and aboveand supported by the side walls of the joist-shaping means providingsupports for the intervening coder-shaping means and of sufiicient widthto support the latter to agree with the chosen joist spacing, and meansof suflicient width for closing the spaces between the coder-shapingmeans in the direction of the joists to permit selective spacing of thedesired number of coder-shaping means, said space-closing means betweenpairs of adjacent coder-shaping means including an offset means carriedby each-individual Coffer-shaping means and. engaging the successivecoffershaping means for closing the space therebetween.

3. A mold comprising spaced joist forms, ceiling supporting meansbridging the space between the adjacent portions of adjacent. joistforms and supported by the upper edges thereof, means of approximatelythe depth of and situated between the joist forms and extending across aconsiderable portion of the space between adjacent joist forms andhaving ends terminating adjacent the exterior sides thereof and havingits tween the joist forms and extending across a considerable portion ofthe space between adjacent joist forms and having ends terminatingadjacent the exterior sides thereof and having its upper portionengaging the lower face of said bridging means for transverselysupporting the same, wedge means interposed between the ends and thejoist form sides by which the second mentioned means is wedged betweenadjacent sides of adjacent joist forms and opposes the lateral pressuretherefrom near the base of said joist forms, and a purlin upon which thejoist forms are rested, said second mentioned means being independentlyand coextensively support-e ed upon said purlin and said wedge meansbeing independent of said purlin.

5. A mold comprising form means for spaced joists and an intermediateceiling, a purlin upon which the lower portions of the joist formportion of the means is rested, a spreader placed edgeon upon and lyingalong the purlin between the 85 a; joist form portions of said formmeans and extending substantially across the spaced portions thereof andof a width substantially that of the depth of the joist forms forsupporting the ceiling portion of said form means upon the purlin, andoperatively engaging the lower portions of the joist portion of the formmeans for sustaining the lateral pressure therebetween immediatelyadjacent the purlin, and means carried by the spreader and straddlingthe purlin so as to loosely hold the spreader in place thereon, wherebythe ceiling load is transmitted as a distributed load throughoutthelength of the spreader and directly to the purlin and the joist load istrans-, mitted directly to the purlin andsubstantially independently ofeach other and in non-cumulative but successive application thereto andwhereby lateral pressure between the joist forming portions of the formmeans is not applied to the purlin.

6. A device as defined by claim 5, characterized by the addition ofwedge means driven between one end of the spreader and the adjacentjoist forming portionof said form means immediately adjacent the purlinfor fixing the spreader in position in the space between the joistforming portions of the form means irrespective of the purlin andconfining the lower portions of adjacent portions of adjacent joistforms against spreading. V

'7. A device as defined by claim 5, characterized by the addition ofwedge means driven between each end of the spreader and the adjacentjoist forming portion of said form means immediately adjacent the purlinfor fixing the spreader in position in the space between the joistforming portions of the form means irrespective of the purlin andconfining the lower portions of adjacent portions of adjacent joistforms against spreading.

JOHN T. BLAIR. JOSEPH E. BLAIR.

